This is a remake of an older work I did over on TLKFAA (my username is "LionessGwen") which you can see here: https://fanart.lionking.org/picture/574824/FANARTTLKLifesNotFair.jpg

My headcanon for this guy is just the same as about 90% of the rest of the fandom: Nuka is Scar's son, but given his klutzy stupid nature, Scar went with the better option of Kovu and just adopted him as his heir in the sequel.

Background is taken from a screenshot of the very scene from the first movie where this great line is said. Any other Lion King fans out there feel free to chat with me!